BASH CGI - pinger - realtime output

[elluk]

Hi all,

I have quickly crafted a small ping script and published with apache for internal troubleshooting. It works ok, but i really wanted realtime line by line feedback for the ping results, but it all comes at once.

Could anyone suggest how I can get said realtime style output?

Thanks!



#!/bin/sh

echo Content-type: text/html
echo ""

if [[ "$QUERY_STRING" =~ "pingntrace" ]]
then
if [[ "$QUERY_STRING" =~ "&pingntrace" ]]
then
echo "Sh1t detected. Quitting"
exit 1
fi

ip=`echo "$QUERY_STRING"|cut -d "&" -f1|cut -d "=" -f2`

cleanip=${ip//[^a-zA-Z0-9.]/}
cleanip=`echo -n $cleanip | tr A-Z a-z`

echo "<h3>Pinging $cleanip...</h3>"
ping -c 4 "$cleanip" 2>&1|sed 's/$/<br>/g'
echo "<hr>"
echo "<p>"
echo "<h3>Tracing route to $cleanip...</h3>"
traceroute -n "$cleanip" 2>&1|sed 's/$/<br>/g'
echo "<hr>"
fi

echo "<form method=get action=\"pinger\">"
echo "<input type=text name=pingntrace>"
echo "<input type=submit value=\"Ping & Trace\"><p>"
echo "</form>"

[atreyu]

Try using the pre HTML tag, e.g.:

#!/bin/sh

echo Content-type: text/html
echo ""

if [[ "$QUERY_STRING" =~ "pingntrace" ]]
then
if [[ "$QUERY_STRING" =~ "&pingntrace" ]]
then
echo "Sh1t detected. Quitting"
exit 1
fi

ip=`echo "$QUERY_STRING"|cut -d "&" -f1|cut -d "=" -f2`

cleanip=${ip//[^a-zA-Z0-9.]/}
cleanip=`echo -n $cleanip | tr A-Z a-z`

echo "<h3>Pinging $cleanip...</h3>"
printf "<pre>\n"
ping -c 4 "$cleanip"
printf "</pre>\n"
#ping -c 4 "$cleanip" 2>&1|sed 's/$/<br>/g'
echo "<hr>"
echo "<p>"
echo "<h3>Tracing route to $cleanip...</h3>"
printf "<pre>\n"
traceroute -n "$cleanip"
printf "</pre>\n"
#traceroute -n "$cleanip" 2>&1|sed 's/$/<br>/g'
echo "<hr>"
fi

echo "<form method=get action=\"pinger\">"
echo "<input type=text name=pingntrace>"
echo "<input type=submit value=\"Ping & Trace\"><p>"
echo "</form>"

[elluk]

genius! that is more or less perfect!! THANK YOU!!!

....errr... why the hell does this work!?!?
and how did you come across it?

thanks again.

[atreyu]

actually, i think it has more to do with print/printf versus the pre tag. maybe the print is buffering and the printf is not-buffering? Anyway, the pre tag sends text input as-is, so maybe it is a combination of things, not sure.

I use the pre tag a lot when I'm doing CGI stuff and want to send the output of system commands to the browser "read-time". But I use Perl, not Bash, for CGI and I'm sure to set buffer flushing on ($| = 1) so that stuff printed gets sent to the screen immediately. That's why I think it has to do with print/printf. Just a guess.

[elluk]

I think perhaps it is sed that is doing the buffering? i did attempt the unbuffer command but i dont think that helps once i hit the sed through a pipe.

i'll have a play with echo, print, printf, sed, unbuffer e.t.c and post if anything interesting comes up.

THANKS AGAIN!!

actually, i think it has more to do with print/printf versus the pre tag. maybe the print is buffering and the printf is not-buffering? Anyway, the pre tag sends text input as-is, so maybe it is a combination of things, not sure.

I use the pre tag a lot when I'm doing CGI stuff and want to send the output of system commands to the browser "read-time". But I use Perl, not Bash, for CGI and I'm sure to set buffer flushing on ($| = 1) so that stuff printed gets sent to the screen immediately. That's why I think it has to do with print/printf. Just a guess.